Plastic packaging uses nearly 40% of all polymers, a substantial share of which is used for consumer products, such as personal care packages (e.g., shampoo, conditioner, and soap bottles) and household packages (e.g., for laundry detergent and cleaning compositions). Most of the materials used to produce polymers for plastic packaging applications, such as polyethylene, polyethylene terephthalate, and polypropylene, are derived from monomers (e.g., ethylene, propylene, terephthalic acid, ethylene glycol), which are obtained from non-renewable, fossil-based resources, such as petroleum, natural gas, and coal. Thus, the price and availability of the petroleum, natural gas, and coal feedstock ultimately have a significant impact on the price of polymers used for plastic packaging materials. As the worldwide price of petroleum, natural gas, and/or coal escalates, so does the price of plastic packaging materials. Furthermore, many consumers display an aversion to purchasing products that are derived from petrochemicals. In some instances, consumers are hesitant to purchase products made from limited non-renewable resources (e.g., petroleum, natural gas and coal). Other consumers may have adverse perceptions about products derived from petrochemicals as being “unnatural” or not environmentally friendly.
In response, producers of plastic packages have begun to use polymers derived from renewable resources to produce parts of their packages. For example, polyethylene terephthalate (PET) that is about 30% renewable (i.e., 30% of the monomers used to form PET, such as ethylene glycol, are derived from renewable resources) has been used for the formation of soft drink bottles. Further, polylactic acid (PLA) derived from corn has been used for plastic packaging purposes. Although containers made from PLA are biodegradable and environmentally friendly, they are currently unfit for long-term preservation because of their sensitivity to heat, shock, and moisture. Packages derived from PLA also tend to shrivel up, shrink, and often break down when exposed to household chemicals, such as bleach and alcohol ethoxylate (i.e., the active ingredient in Mr. Clean®), when the PLA is in direct contact with the product. Parts of food packaging and containers used to hold personal care products have also been formed from polyethylene derived from a renewable resource.
Although the current plastic packaging in the art can be partially composed of polymers derived from renewable materials, this current packaging contains at least one component (e.g., container, cap, label) that includes at least some virgin petroleum-based material, such as polyethylene, polyethylene terephthalate, or polypropylene. None of the current plastic packaging is substantially free of virgin petroleum-based compounds, 100% sustainable, and 100% recyclable, while having a shelf life of at least two years.
Current plastic packaging also can face difficulties during recycling. In the first few steps of a typical recycling procedure, a commonly used floatation process is used to separate polymers in a mixture based on density. Polymers that are more dense than water, such as polyethylene terephthalate, sink to the bottom of a solution, while polymers that are less dense than water, such as polyethylene and polypropylene, rise to the top of the solution. Contamination issues frequently occur during recycling because current plastic packaging that is highly filled or that is composed of some renewable materials often contains dense materials that sink during the floatation process and contaminate the polyethylene terephthalate stream (e.g., polylactic acid, highly filled high density polyethylene, or highly filled polypropylene). The polyethylene terephthalate stream is very sensitive to contamination, while the polyethylene stream is typically more robust.
Accordingly, it would be desirable to provide plastic packaging that is substantially free of virgin petroleum-based compounds, 100% sustainable, 100% recyclable, has a long-lasting shelf life, and that can minimize or eliminate contamination during recycling.